After providing some examples of contradictory economic policy advice, we characterise different conceptions of policy advice. This is possible because, in many situations, neither economic theory nor empirical analyses provide unambiguous answers to policy questions. Thus, contradictory advice by different economists is often possible without violating scientific standards. Thus, in the process of seeking policy advice, politicians and interest groups will engage scientists with similar political ideologies. In this situation, the objectivity of political advice is still possible, but only if there is an open discussion and, in the case of empirical analyses, if data are available for re-estimations.